Embodiments of the present invention relate to a touch screen and a manufacturing method.
FIG. 1 is a structural view showing a conventional touch screen. In FIG. 1, a normal resistance type touch screen is shown as an example. This touch screen comprises a display unit for displaying and a touch unit for sensing a touch signal. The display unit comprises an array substrate 11, a color filter substrate 12 and a liquid crystal layer 13 sandwiched between the array substrate 11 and the color filter substrate 12. The touch unit comprises an upper substrate 14 and a lower substrate 15. An indium tin oxide (ITO) layer 16 is applied on the surface of the upper substrate 14 opposing to the lower substrate 15, and another ITO layer 16 is applied on the surface of the lower substrate 15 opposing to the upper substrate 14. Insulating particles 17 are filled between the two ITO layers to separate the upper substrate 14 and the lower substrate 15. The color filter substrate 12 and the lower substrate 15 are bonded together for example by optically clear adhesive (OCA) 18. Cover lenses are further attached on the upper substrate 14. When the touch unit is touched, the ITO layer of the upper substrate 14 and the ITO layer of the lower substrate 15 come into contact at the touched point. In this case, by respectively applying a voltage signal to the Y axis electrode on the lower substrate 14 and to the X axis electrode on the upper substrate 15, the voltage at the touched point is obtained based on the phenomenon that voltage drop occurs due to the contact resistance, and then the coordinates at the touched point can be determined. Since the touch screen has a four-layer structure comprising the array substrate, the color filter substrate, the lower substrate and the upper substrate as described above, the touch screen has the disadvantages of a large thickness and low light-transmittance. At present, the thickness of the touch screen is preferable to be decreased by decreasing the thicknesses of the substrates in the display unit and/or the touch unit or by replacing the cover lenses attached on the upper substrate with a polarizer sheet.